Electric incandescent lamp



7, 1938. H. ASMUSSEN ET m. 2142072 ELEC'IRIC INC'ANDESCEN'I LAMP Filed Sept. 23, 1937 "'l1mvehtors:

Heinrich Asmussern, Hans Normann von Funcke,

Patented Dec. 27, 1938 ELECTRIC INCANDESCENT LAM1 Heinrich Asmussen, Berlin-Steglltz, am! Hans- Normann von Funcke, Berlin-Halensee, Germany, assignors to General Electrie Company, a corporation o! New York Appllcation September 23, 1937, Serial N0. 165,406 In Germany October 26, 1936 3 Claims.

Our invention relates to elecfirie incandescent lamps and slmllar devlces comprising a bulb hav- Ing an electrical energy translation element, such a.s a. fllament, sealed therein and a base mounted on sald. bulb. More particularly, our invention relates to bases for said devices and still more particularly to so-called mechanical bases in whlch the usual cement which unites the base to the glass bulb is eliminated.

An object of our inventlon is to provide an improved mechanical base construction for electrlcincandescent lamps in which the base is firmly secured to thebulb neck by mechanical means, and in which the side lead wire is positively counected o1 soldered I;o the base shell.

According to the invention, the one lead er current supply wire which is connected to the base shell is inserted in a longitudinal slot in the bulb neck, and is led under an inner semicircular sheet metal strip mechanically secu1'ed to the bulb neck to the outside of the base, where it is then bent over the edge o1 the base shell so as to lie opposite an elongated circumferential slit; formed in the base shell adjacent the edge thereof, said slit being so located on the shell with respect; to the th.reads thereon as to positlon the slit opposite both the longitudinal slot in the bulb neckand the sheet metal strip when the base is screwed in plane on the bulb neck. With the parts in such assen'1bled position, it is readily possible to solder, in a visible manner, the base to the inserted semi-circular metal str1p und also the lead wire to the base by means of a drop 015 solder applied externally to such parts at the aforesaid .elongated. s1it in the base shell.

The invention will be better understood by reference to the following detailed description of a specles thereof taken in connection with the accompanying drawing.

In the drawing, Flg. 1 1s an elevation of the bulb und. base portions of a lamp constructed in accordance with our invention, with the base shown in posltion preparatory to the application of the same to the bulb; Fig. 2 is an elevation 015 a. completed lamp comprising our invention; und Fig. 3 15 a sectional view on an enlarged sca.le taken on the line 3-3 of Flg. 1.

- Reterring to the dra.wing, the neck I'0f the glass bulb 2 is provided with a thread 3, a longitudinal slot l, and two substantially diametrlca.lly opposite pan-shaped indentations 5, 5 located between the glass thread 3 a.nd the bulbous portion 015 the bulb. -A semi-clrcular strip o! sheet metal Ii, the ends of which a.re provided w'lth pall-shabed protuberances l, l corresponding to the indentations 5, 5 in the bulb neck, ls secured around the bulb neck so as to partially surround the same by the interfitting engagement 01 the protuberances I, I withln the bulb neck indentatlons 5, 5. The said strlp of sheet metal 6 ls so applied to the bulb neck as to overlie the longitudinal slot 4 therein.

'I'he base which is to be screwed onto the glass thread 3 comprises a screw threaded metal shell or sleeve 8, insulation 9, and a metal eyelet III. The threads on the base shell 8 are so formed as to solidly screw onto the glass thread 3 on the bulb .neck. The eyelet I0 and the shell 8 are electrically connected to the fllament (not shown) of the lamp by leads II and I2 respectively. Lead II extends through a central hole in the insulation 9 and eyelet III and is either soldered or welded to said eyelet to thereby form the bottom or center contact. Lead I2 is bent over the end wa1l of the bulb neck into the longitudinal groove 4 therein, and extends under the sheet metal strip 6 (Fig. 3) to the edge. or rim o! the base shell 8 around which it is bent am! then soldered or welded to the outer surface of said. shell.

'1o positively insure the soldering of the lead I2 and metal strip 5 to the base, the shell 8 is provided with an elongated ciroumferential slit I3 adjacent the edge thereof, said slit being so located with respe'ct to the thread on the shell as to lie opposite both the longitudinal slot 4 in the bulb neck and the metal strip 6 when the base is screwed in place on said bulb neck. 'I'hus the free end of lead I2, when bent over the edge of the base shell 8, will extend over the slit II In said shell. By applying a. drop of solder or other fusible material to the lead I2 at approximately the polnt where lt passes across the slit I3 in the base shell, the said. solder will then connect both the lead I2 and metal strip 6 to the base shell 8. It is therefore possible, with the above described construction, to solder in a visible manner the lead I2 and. metal strip 6 to the base shell 8, thus insuring the positive connection of sa1d parts.

The sheet metal strip I5, by reason of the interengagement of the protixberances l, l thereof within the indent ations 5, 5 in the bulb neck, pre vents tur ning or rotational displacement of the base with respect to the bulb neck. 'For the same reason, the said metal strip 6 eifectively prevents longitudinal displacement 01 the base with reference to the bulb neck. as does the interengagement of the screw threads formed on.

sald bulb neck and the base shell 8. Since the preventlng a.ny

sa.ld threa.ds are solldly screwed together, the base 1s firmly sea.ted on the bulb neck, thereby wabbling of the base on said bulb neck. 1

What we clalm as new and desire to secure by Letters Patent 015 the United States is:

1. An electrlcal device comprlsing a. bulb hav- 1ng a threaded neck port1on provided with a longitudinally extending groov e a. lead wire extending through sa.1d groove, an inner base niember secured aga.inst mtatlonal -displacement to -saidbulb neck and overlying said groove, an

outer base comprising a threaded base shell screwed onto said bulb neck und provided with an elongated circumferentially extending slit disposed substantia.lly opposite salcl groove and sa.ld Xnner base member, seid lead wire extending over the edge of sald shell und a.cross the seid slit thereln, und sa.id shell being electrlcally connected to said lead wire and to said inner base memberbya quantlty of fusible materia] disposed withln und adia.cent said slit.

2. An electrical device comprising a bulb hav- Ing a. threaded neck portion provided wlth a lon- -gitudlnally extendlng groove und. a depression, a lead wire extending through sa.ld groove. an inner be.se member consistlng cf a meta.l strlp extendlng clrcumferentially o1. sa.ld bulb neck and overlylng sald groove and having a protuberance engaginz wlth sa.id bulb neck depression to prevent rotationa.l movement thereof, an outer base c0mprlslng a. threaded base shell scrowed onto sdd bulb nec k and provided with an elongated clrcumferentially extending slit; dlsposed substantlally opposlte sald groove und sa.ld meta.l strlp, sald lea.d wlre extendlng over the edge of sald shell and across the sald slit therein, und said. shell belng electrically connected to seid lead and flrmly secured to said meta.l strlp by a. quantity of Iuslble material dlsposed wlthln und adjacent sa.ld slit.

3. An electrical devlce comprlslng a bulb having a, threa.ded neck portion provided with a longitudlnally extending. groove und a palr ot diamiatrlcally opposed depresslox;s, a lead wlre extendlng through said groove, an inne:- base menber conslstlng o! a seml-clrcular metal strlp extendlng clrcumierentlally o1 sadd bulb neck und overlylng said groove a.nd hflng p fflhlberances at 1ts ends engaglng with sa.ld bulb nach depresslons to prevent rotatlonal movexnent thereof. an outer baue comprising a thresded base; shell flrmly screwed o1ito sah! bulb noch and provlded with an elong ated clrcumterentially extending slit so located wlth rel'erence to the thread on sa.ld shell as to lle oppodte sa.ld groove und saldmetal strip when sald shell In screwed'in place on sa.ld bulb neck, sa.id leod wlre extending over. the edge 01 sa1d shell und across the sa.ld slit thereln, und sald shell beta: electrically connected to und lead. wire und finn- 1y secured to said metal strip by a. quantlty 01 fuslble material dlsposed withln und adjwent 30 sa.ld slit.

HEINRICH ASMUSSEN. HA .NS-NORMAN von FUNCKE. 

